Papers by Keyword: Biomechanical Properties

Abstract: This work presents an experimental program to determine the mechanical properties of cancellous bone in the femoral head as a function of location. To achieve this several specimens of cancellous bone of approximately 10 mm height and 10 mm diameter were obtained from one human femoral head, starting the sampling from its main loading compressive direction. All specimens underwent compression testing in order to determine the mechanical properties of each specimen and thus a properties map of the cancellous bone in the femoral head was obtained. Based on the results a parametric file with material properties was created in order to be used by professionals in finite element analysis programs.

Abstract: This paper deals with evaluation of mechanical properties of human trabeculae in the interconnection area. Local changes in the trabecular connections were evaluated using both quasi-static nanoindenation and modulus mapping technique. Connecting point of two trabeculae was revealed by precise grinding and polishing. A rectangular region in the interconnection was selected and inspected by modulus mapping procedure. Moreover several quasi-static indentation measurements using cube-corner indenter were performed along distinct lamellae. The obtained elastic properties were then compared with the values of the rod-like trabeculae. The comparison does not indicate significant differences in elastic properties between the trabecular rods and interconnections.

Abstract: The skin, which acts as a protector of the body from potentially harmful external environment is a multi-layered tissue that exhibits complex mechanical behaviour. The aim of this paper is to review available studies of human skin using experimental and numerical methods in determining the mechanical properties of skin. Mechanical properties of skin are vital to the certain industries such as surgical, cosmetics, forensic science and etc., where skin study currently leads to the development of an ultimate skin-like substitute that contains anatomy and physiology characteristics. A number of research papers and journals related to skin were revised and currently findings show that available information in regard to skin biomechanical properties is limited and the actual skin behavior is not comprehensively examined. Nevertheless, further in-depth research is required to develop appropriate techniques in estimating the skin properties which are valuable to the development of biomechanics study of skin.

Abstract: Quartz Fibre/nano-Hydroxyapatite/Polyamide 66(QF/n-HA/PA66) composite was prepared by extrusion molding method. The QF is well dispersed in the nano-hydroxyapatite/polyamide 66 matrix and some interaction and new interface formed between QF and n-HA/PA66. Tensile strength, compressive strength and flexural strength of the 38wt%QF/n-HA/PA66 composite reached 81 MPa, 190 MPa and 195 MPa, which were higher than those of human cortical bone. Mechinical properties were improved with the increasing of QF content and QF well enhanced biomechanical properties of the composite. Based on the excellent biomechanical properties of composites, the long load-bearing thigh bone substitute was fabricated for tumour infected thigh bone patient.

Abstract: To analyze the importance of bone quality, we studied 21 primary compressive trabecular system by micro-computed tomography(micro-CT), finite element analysis and destructive mechanical test. Significant correlations were found between histomorphometry and biomechanical parameters. The results indicate that the bone quality of primary compressive trabecular system is determined more by its combined micro-structural parameters (histomorphometry) and biomechanical parameters than histomorphometry only. Assessment of trabecular bone by finite element analysis may become important not only for assessment of bone quality but also for prediction of bone fracture risk of bone degeneration.

Abstract: The purpose of this research is to find out the interaction between histological alterations and mechanical properties of engineered tendon implanted in situ. Defects of 0.5cm-1.0cm were made at deep flexor tendons by surgical procedure. Engineered tendons using degradable scaffolds polyglytic acid (PGA) mesh and tendon cells were implanted to repair the defects. Chickens were killed respectively at 2 weeks, 4 weeks, 6 weeks, and 8 weeks after surgery. The implants were taken out for histological examination, biomechanical test, and collagen synthesis assay. The results showed that after surgery the PGA scaffolds degraded fast and took precedence of collagen synthesis. There were not enough amount and maturation of the collagen fibers of the new tendon at 2-8 weeks after surgery. The biomechanical properties of new tendons were less than those of the normal tendon. Therefore, it is necessary to construct engineered tendons with better degradation rate of scaffolds and suitable biomechanical stimulation so that more collagen synthesis and better biomechanical properties of new tendons can be developed early after implantation.